【Flyer杀G作文组】7月28日Argument142-By 但我

但我UID: 2763822

ARGUMENT 142
142. The article entitled 'Eating Iron' in last month's issue of Eating for Health reported that a recent study found a correlation between high levels of iron in the diet and an increased risk of heart disease. Further, it is well established that there is a link between large amounts of red meat in the diet and heart disease, and red meat is high in iron. On the basis of the study and the well-established link between red meat and heart disease, we can conclude that the correlation between high iron levels and heart disease, then, is most probably a function of the correlation between red meat and heart disease.

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TOPIC: ARGUMENT142 - The article entitled 'Eating Iron' in last month's issue of Eating for Health reported that a recent study found a correlation between high levels of iron in the diet and an increased risk of heart disease. Further, it is well established that there is a link between large amounts of red meat in the diet and heart disease, and red meat is high in iron. On the basis of the study and the well-established link between red meat and heart disease, we can conclude that the correlation between high iron levels and heart disease, then, is most probably a function of the correlation between red meat and heart disease.
WORDS: 506
TIME: 00:30:00
DATE: 2010/7/29 11:31:33


The author cities a study correlating the amount of iron in a person’s diet with the risk of heart disease. He/she also cities a well-established correlation between high amount of red meat and the incidence of heart disease. The author concludes that the link between high iron levels and heart disease is most probably a function of the connection between red meat and heart disease. However, I find the argument suffers from a series of flaws which make it specious.

The argument's chief problem is that it relies on a study which is not necessarily reliable. In order to establish a strong relationship between iron in the diet and the risk of heart disease, the study's samples must be sufficient in size and representative of the overall population of heart disease. Lacking evidence of a sufficiently representative sample, the author cannot justifiably depend on the study to draw any conclusion whatsoever.

Even assuming that the study is reliable, a direct correlation between iron and heart disease does not necessarily ensure that the former causes the latter. While a high correlation is strong evidence of a causal relationship, in itself it is not sufficient. The arguer must allow for all other possible factors leading to heart disease, such as genetic propensity, amount of exercise, and so forth. Lacking evidence that the heart-disease sufferers whom the study observed were similar in all such respects, the author cannot justifiably conclude that a high-iron diet is the primary cause, or even a contributing cause, of heart disease.

Similarly, a correlation between red meat and heart disease may not prove the causal link between them either. Lacking evidence to the contrary, it is possible that red-meat eaters are comparatively likely to incur heart disease due to other factors that have nothing to do with the amount of red meat in their diet. For the people whose diets are high in iron may happen to the same group who often overeat and lack exercising, or perhaps the excess of fat rather than red meat itself contributes to heart disease. The author must consider and eliminate all this and other possibilities why red-meat eaters are likely than other people to suffer from heart disease. Otherwise, I cannot accept the author's implicit claim that eating red meat is any more likely to cause heart disease than eating other foods.

Even if the causal correlation between iron and heart disease is well grounded, the author didn't rule out that eating much red meat will lead to high amount of iron absorption. Maybe the iron in red meat has a low chance of being absorbed. Without accounting for this possible factor the author cannot convincingly conclude from the study that red meat is the chief cause of heart disease.

In sum, the scant evidence the author cities proves nothing about the
chief reason for heart disease is high-iron diets,
the author unfairly assumes that correlation is tantamount to causation. To strengthen it the author must show that it is high iron rather than other possibilities that lead to heart disease. Besides, whether eating high amount of red meat will lead to high absorption of iron still requires investigation.